The subject matter disclosed herein relates to measuring tie-bolt strain in hyper reciprocating compressors.
Hyper reciprocating compressors are used to generate high pressures in industrial settings. For example, hyper reciprocating compressors may generate pressures up to 3500 bar (50,000 psi). The compressors may be used compress ethylene, polyethelene, low-density polyethylene (LDPE), or other suitable substances. Due to the high pressures in the compressor, it becomes difficult to measure pressures inside these compressors traditional methods of intrusive pressure measurement are impractical. To intrusively measure the pressure inside the compressor, a hole typically must be drilled into a cylinder of the compressor, equipment passed through the hole, and the hole resealed to withstand the high pressures.
Alternatively, compressors may rely on non-intrusive measurement, such as using a resistive strain gauge on a modified tie-bolt. However, to modify and install the tie-bolt is costly and requires much time. Furthermore, when the compressors undergo maintenance, the tie-bolt might be replaced or misplaced, thereby an operator loses the ability to monitor the compressor via the resistive strain gauge on the modified tie-bolt. In other compressors, a mechanical clamp-on style resistive strain gauge may be used. Although the clamp-on style resistive strain gauge may be removed at will, these gauges have a limited frequency response (dynamic strain) and often have issues with low signal-to-noise ratios (SNR), gauge creep, or the connection between the gauge and the measured component may be lost due to mechanical failure (e.g., glue fails). Accordingly, it is desirable to provide non-intrusive measurement systems and techniques that overcome the deficiencies of present systems, as described above.